Our standard of living is roughly determined by all the goods and services we produce divided by the number of people consuming those goods and services. The only proven way to improve our standard of living is to increase our productivity.

An "illegal" working in the U.S. is certainly more productive working here than working in their home country- it they weren't they wouldn't bother coming here. Add up all the individual improvements in productivity and you have a huge increase in world productivity- which axiomatically raises the world standard of living.

A case can be made that the standard of living goes up most in the countries that host immigrant labor. Countries that host immigrant labor force their citizens to compete as world citizens for the available jobs. This provides a powerful stimulus for citizens to make the personal investment in education and training to increase their personal productivity and therefore their own standard of living.

The world economy, for the foreseeable future, has a lot of jobs that are most economically done by people rather than machines. Doesn't it make a lot of sense for the guy at the end of the shovel to be an illiterate immigrant who's happy to have the job rather than an educated citizen who can be much more productive doing something else?

The main problem with illegal aliens is that they are illegal. Let's control our borders to keep out terrorists while welcoming the millions of hard working honest folks who would love to become a part of the American Dream.